In this case special conditions occur in many areas, for example in the filling of juices. In this way it is necessary for the entire treatment of the containers and also the closure thereof to be carried out inside a sterile or clean space. In this case a longitudinal movement of a closure head with respect to a longitudinal direction of the containers is also necessary to some extent for the closure procedure. Since it is not normally desired for all the elements which are necessary for a longitudinal movement of this type to be placed in the interior of the sterile space, as this would run counter to keeping the latter sterile, attempts have been made to place as many drive elements as possible outside the sterile space. On account of the conditions of the stroke of the closure element which are necessary in a closing means, however, the situation arises that the non-sterile machine parts present outside the sterile space or below a carrier ring project into the sterile region or move into the sterile space. In this way, it is possible for germs to penetrate into the sterile region.
Various apparatus are known from the prior art to achieve a separation between the sterile and non-sterile spaces even in the case of elements moving in this manner. In this way a surge tank or a vapour barrier is provided in some cases to carry out a sealing of this type. On account of the large stroke or the thermal stressing of the components, however, these sealing means can be used to only a limited extent or are difficult to implement.
A machine for the aseptic treatment of containers is known from WO 2004/065283. This has a surge tank in order to separate a rotationally movable part from a stationary region in a sterile manner.
The object of the present invention is therefore to provide an apparatus for closing containers which is also capable of handling comparatively large reciprocating movements of a closure element. This is attained according to the invention by an apparatus according to claim 1. Advantageous embodiments and further developments form the subject matter of the sub-claims.